Hi Andreas, Good to hear that you've been able recreate the deadlock, your description is really useful. How long does it take before you start seeing the dealocks? I'd like to have another bash at spotting it. I'm tempted to come up with a way for the DatabasePager to spot a deadlock and reported once it happens as there is chance when I'm leaving the app running it's deadlocking but I never spot the problem.
Robert. On Thu, May 27, 2010 at 1:37 PM, Andreas Malzahn <[email protected]> wrote: > Hi Robert, > > I tested with the current trunk, using osgViewer and environment variables: > OSG_NUM_DATABASE_THREADS=4 > OSG_NUM_HTTP_DATABASE_THREADS=0 > > Also I used a large vpb generated .ive with is generated with the latest > version - some ealier versions have the tileID not correctly saved somehow, > which might prevent the deadlock from occuring. > > After some moving around I got still the deadlock, the stack is at the end of > this post. There are 4 threads with a similar stack, and the threads wait for > each other. The osgViewer is actually not hanging - you can move around, but > the tiles are not updated any more. YOu have to pause the debugger and look > at the stack to see the deadlock. > > The Problem is in the lines like: > if (updateNeighboursImmediately) right_tile->init(dirtyMask, > true); > > One thread will try to init() the right neighbor, while another thread will > init() the left neighbor, then the thread deadlock because they lock first > thier own _writeBufferMutex, and then try to lock the _writeBufferMutex of > the neighbour. > I think for this setting updateNeighboursImmediately=false is a good > solution. Another option is to use tryLock() on the neighbours - and if this > fails, set the neighbours as dirty as in updateNeighboursImmediately=false > > There is still the other deadlock within the Terrain class, for with I > proposed a solution before. > > Regards, > Andreas > > ot12-OpenThreadsd.dll!OpenThreads::Mutex::lock() Line 113 + 0xc bytes > C++ > > osg66-osgTerraind.dll!OpenThreads::ScopedLock<OpenThreads::Mutex>::ScopedLock<OpenThreads::Mutex>(OpenThreads::Mutex > & m={...}) Line 31 + 0x2a bytes C++ > osg66-osgTerraind.dll!osgTerrain::GeometryTechnique::init(int > dirtyMask=1023, bool assumeMultiThreaded=true) Line 104 + 0xf bytes C++ > osg66-osgTerraind.dll!osgTerrain::TerrainTile::init(int > dirtyMask=1023, bool assumeMultiThreaded=true) Line 184 + 0x29 bytes C++ >> >> osg66-osgTerraind.dll!osgTerrain::GeometryTechnique::generateGeometry(osgTerrain::GeometryTechnique::BufferData >> & buffer={...}, osgTerrain::Locator * masterLocator=0x0d926e58, const >> osg::Vec3d & centerModel={...}) Line 953 + 0x26 bytes C++ > osg66-osgTerraind.dll!osgTerrain::GeometryTechnique::init(int > dirtyMask=1023, bool assumeMultiThreaded=false) Line 137 + 0x20 bytes C++ > osg66-osgTerraind.dll!osgTerrain::TerrainTile::init(int > dirtyMask=1023, bool assumeMultiThreaded=false) Line 184 + 0x29 bytes C++ > > osg66-osgTerraind.dll!osgTerrain::TerrainTile::traverse(osg::NodeVisitor & > nv={...}) Line 145 C++ > osg66-osgd.dll!osg::NodeVisitor::traverse(osg::Node & node={...}) > Line 191 + 0x1c bytes C++ > > osg66-osgDBd.dll!osgDB::DatabasePager::FindCompileableGLObjectsVisitor::apply(osg::Node > & node={...}) Line 139 + 0xf bytes C++ > osg66-osgd.dll!osg::NodeVisitor::apply(osg::Group & node={...}) Line > 86 + 0x13 bytes C++ > osg66-osgTerraind.dll!osgTerrain::TerrainTile::accept(osg::NodeVisitor > & nv={...}) Line 76 + 0x55 bytes C++ > osg66-osgd.dll!osg::NodeAcceptOp::operator()(osg::ref_ptr<osg::Node> > node={...}) Line 356 + 0x5e bytes C++ > > osg66-osgd.dll!std::for_each<std::_Vector_iterator<osg::ref_ptr<osg::Node>,std::allocator<osg::ref_ptr<osg::Node> > > > >,osg::NodeAcceptOp>(std::_Vector_iterator<osg::ref_ptr<osg::Node>,std::allocator<osg::ref_ptr<osg::Node> > > > _First={_ptr=0x0d926c70 }, > std::_Vector_iterator<osg::ref_ptr<osg::Node>,std::allocator<osg::ref_ptr<osg::Node> > > > _Last={_ptr=0xfdfdfdfd }, osg::NodeAcceptOp _Func={...}) Line 29 + 0x1f > bytes C++ > osg66-osgd.dll!osg::PagedLOD::traverse(osg::NodeVisitor & nv={...}) > Line 136 + 0x6c bytes C++ > osg66-osgd.dll!osg::NodeVisitor::traverse(osg::Node & node={...}) > Line 191 + 0x1c bytes C++ > > osg66-osgDBd.dll!osgDB::DatabasePager::FindCompileableGLObjectsVisitor::apply(osg::Node > & node={...}) Line 139 + 0xf bytes C++ > osg66-osgd.dll!osg::NodeVisitor::apply(osg::Group & node={...}) Line > 86 + 0x13 bytes C++ > osg66-osgd.dll!osg::NodeVisitor::apply(osg::LOD & node={...}) Line > 156 + 0x13 bytes C++ > osg66-osgd.dll!osg::NodeVisitor::apply(osg::PagedLOD & node={...}) > Line 161 + 0x13 bytes C++ > osg66-osgd.dll!osg::PagedLOD::accept(osg::NodeVisitor & nv={...}) > Line 32 + 0x41 bytes C++ > osg66-osgd.dll!osg::Group::traverse(osg::NodeVisitor & nv={...}) Line > 62 + 0x25 bytes C++ > osg66-osgd.dll!osg::NodeVisitor::traverse(osg::Node & node={...}) > Line 191 + 0x1c bytes C++ > > osg66-osgDBd.dll!osgDB::DatabasePager::FindCompileableGLObjectsVisitor::apply(osg::Node > & node={...}) Line 139 + 0xf bytes C++ > osg66-osgd.dll!osg::NodeVisitor::apply(osg::Group & node={...}) Line > 86 + 0x13 bytes C++ > osg66-osgd.dll!osg::Group::accept(osg::NodeVisitor & nv={...}) Line > 38 + 0x41 bytes C++ > osg66-osgDBd.dll!osgDB::DatabasePager::DatabaseThread::run() Line 741 > + 0x34 bytes C++ > > ot12-OpenThreadsd.dll!OpenThreads::ThreadPrivateActions::StartThread(void * > data=0x00e47614) Line 113 + 0xf bytes C++ > msvcr90d.dll!_callthreadstartex() Line 348 + 0xf bytes C > msvcr90d.dll!_threadstartex(void * ptd=0x02f99a60) Line 331 C > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=28278#28278 > > > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
